武汉城市群热岛效应对土地利用响应及其预测

Prediction of Wuhan Urban Agglomeration Urban Heat Island and Its Response to Land Use

城市化造成城市土地利用急剧变化并加剧城市热岛效应,已成为城市气候演变研究的热点之一。基于武汉城市群2005-2015年3期MOD11A2地表温度数据,以景观格局指数表征土地利用空间格局特征,建立城市热岛与土地利用空间格局之间的回归模型;通过CA-Markov模型模拟2030年武汉城市群土地利用变化(精度为80.16%)并预测现有土地利用变化趋势下城市热岛效应演变规律。结果表明:(1)武汉城市群2005-2015年月平均温度升高,夏季热岛效应稳定,秋冬季热岛效应增强;(2)热岛效应由武汉市城区逐渐向周边城区扩散,热岛强度变化与城市空间发展吻合;(3)林地的聚集、形状、水域的面积和建设用地的密度是影响城市热岛效应的重要因子;(4)预测2030年武汉城市群林地面积将减少,建设用地面积增加;基于土地利用数据预测2030年武汉市城市群城乡温差增大,城市热岛效应增强,城市扩张所带来的建设用地增加、林地减少是城市热岛增强及空间上扩张的主要原因。

The land use changes caused by urbanization have been thought as one of major causes for the phenomenon of urban heat island (UHI),which has been a globally hot spot of urban climate studies.Based on MOD11A2 land surface temperature data of Wuhan Urban Agglomeration (WUA)from 2005 to 2015,landscape metrics indexes were employed to characterize land use pattern,and then the regress model was built up to reflect relationship between UHI and the spatial pattern of land use.By the CA-Markov model,the spatial land use pattern in 2030 was predicted with an accuracy of 80.16%,based on which the future of UHI has been evaluated and analyzed for WUA.The results showed that WUA suffered a month mean temperature increase from 2005to 2015,and to be specific the UHI in summer was stable while the UHI in fall and winter became stronger.The heat island intensity gradually spread from the urban area of Wuhan to the surrounding suburban area,which was consistent with the scale of urban sprawl.The aggregation and shape of forest land,the area of water body and the density of construction land were important factors that affect the urban heat island intensity.It predicted that the area of forest in WUA would drop in 2030 and construction would increase,which would lead to an enhanced UHI,and the increase of construction land and decrease of forest brought by urban sprawl were main reasons of the strengthened and spatially expanded UHI in 2030.